JLG 45e Service Manual - Manual (Page 29)

SECTION -
3120861 – JLG Lift – -3
2. JLG recommends Mobilfluid 424 Hydraulic Oil,
which has an SAE viscosity of 10W-30 and a viscos-
ity index of 152.
NOTE: Start-up of hydraulic system with oil temperatures
below -15 degrees F. is not recommended. If it is
necessary to start the system in a sub-zero environ-
ment, it will be necessary to heat the oil with a low
density 100VAC heater to a minimum temperature of
-15 degrees F.
3. The only exception to the above is to drain and fill
the system with Mobil DTE11 oil or its equivalent.
This will allow start up at temperatures down to -20
degrees F. However, use of this oil will give poor per-
formance at temperatures above 120 degrees F.
Systems using DTE11 oil should not be operated at
temperatures above 200 degrees F. under any con-
dition.
Changing Hydraulic Oil.
1. Use of any of the recommended hydraulic oils elimi-
nates the need for changing the oil on a regular
basis. However, filter elements must be changed
after the first 50 hours of operation and every 300
hours thereafter. If it is necessary to change the oil,
use only those oils meeting or exceeding the specifi-
cations appearing in this manual. If unable to obtain
the same type of oil supplied with the machine, con-
sult local supplier for assistance in selecting the
proper equivalent. Avoid mixing petroleum and syn-
thetic base oils. JLG Industries recommends chang-
ing the hydraulic oil every two years.
2. Use every precaution to keep the hydraulic oil clean.
If the oil must be poured from the original container
into another, be sure to clean all possible contami-
nants from the service container. Always clean the
mesh element of the filter and replace the cartridge
any time the system oil is changed.
3. While the unit is shut down, a good preventive main-
tenance measure is to make a thorough inspection
of all hydraulic components, lines, fittings, etc., as
well as a functional check of each system, before
placing the machine back in service.
Lubrication Specifications
Specified lubricants, as recommended by the component
manufacturers, are always the best choice, however,
multi-purpose greases usually have the qualities which
meet a variety of single purpose requirements. Should
any question arise regarding the use of greases in mainte-
nance stock, consult your local supplier for evaluation.
Refer to Table 1-2 for an explanation of the lubricant key
designations appearing in the Lubrication Chart.
2.4 CYLINDERS - THEORY OF OPERATION.
Systems Incorporating Double Acting
Cylinders.
30 electric - Upper Boom Lift, Lower Boom Lift, and
Steer.
35/n35 electric - Upper Boom Lift, Lower Boom Lift,
Telescope, Slave, Master, Rotator, and Steer.
40/n40/45 electric - Upper Boom Lift, Mid Boom Lift,
Lower Boom Lift, Telescope, Slave, Master, Rotator,
and Steer.
A double acting cylinder is one that requires oil flow to
operate the cylinder rod in both directions. Directing oil
(by actuating the corresponding control valve to the pis-
ton side of the cylinder) forces the piston to travel toward
the rod end of the barrel, extending the cylinder rod (pis-
ton attached to rod). When the oil flow is stopped, move-
ment of the rod will stop. By directing oil to the rod side of
the cylinder, the piston will be forced in the opposite direc-
tion and the cylinder rod will retract.
Holding valves are used in the Lift circuits to prevent
retraction of the cylinder rod should a hydraulic line rup-
ture or leak develop between the cylinder and its related
control valve.
2.5 VALVES - THEORY OF OPERATION.
Control Valves.
30 electric - Control Valve 4640725 this valve controls
Swing, Lower Lift, and Upper Lift.
35/n35 electric - Control Valve 4640843 this valve con-
trols Platform, Telescope, Swing, Lower Lift, and Upper
Lift.
40/n40/45 electric - Control Valve 4640797 this valve
controls Platform, Telescope, Swing, Lower Lift, and
Upper Lift.
It consists of cartridge type valves in an anodized alumi-
num manifold. The cartridge valves provide for control of
flow, volume of flow and pressure in the hydraulic system.
The directional control valves are solenoid operated, three
position, 4-way sliding spool type valves. One valve is pro-
vided for each of the three functions. Energizing one of
the electrical coils on a valve will divert the supply of
hydraulic oil to provide motion of that function in one
direction. Energizing the other coil will divert the oil for
motion in the other direction. When neither coil is ener-
gized, the supply of hydraulic oil is blocked.
Flow control valves in the lift circuits provide for control of
the rate of flow when the oil is flowing out of the cap ends
of the cylinders (the load is being lowered). An adjusting
screw on each cartridge flow control valve allows the rate
of flow (speed) to be adjusted. When oil is flowing into the
cap end of the lift cylinders, an internal check valve feature
allows unrestricted flow.